L
- Labral tear, shoulder
- Labyrinthitis
- Lacrimal duct obstruction
- Lacrimal duct stenosis
- Lactose intolerance
- Large for gestational age
- Laryngeal cancer
- Laryngeal dystonia
- Laryngitis
- Laryngotracheobronchitis
- Lateral epicondylitis
- Laxative colitis
- Lazy eye
- LCPD
- Le Fort fracture
- Lead poisoning
- Left hemisphere stroke
- Left ventricular dysfunction
- Left ventricular failure
- Left-side stroke
- Legg-Calve-Perthes Disease
- Legionnaire's disease
- Legionnaire's pneumonia
- Leigh's syndrome
- Leiomyoma
- Leptospirosis
- Lesch-Nyhan syndrome
- Leukemia - adult
- Leukemia - child
- Leukemic reticuloendotheliosis
- Leukodystrophy
- Leukoplakia
- Lewy body dementia
- Lewy body disease
- LGA
- Lice
- Lichen planus
- Ligament sprain
- Limb-Kinetic apraxia
- Lipoma
- Little League elbow
- Liver cancer
- Liver cirrhosis
- Lordosis
- Loss of movement
- Loss of voice
- Lou Gehrig's disease
- Low back pain
- Low blood glucose
- Low blood sugar
- Lower leg break
- Lower respiratory tract infection
- Lower UTI
- Lung cancer
- Lupus, systemic
- Lyme disease
- Lymph gland inflammation
- Lymph node infection
- Lymphedema
- Lymphoma
- Lymphoma, non-hodgkin's - child
- Lysosomal storage disease
- Lysosomal storage disease (glycoprotein storage diseases)
- Lysosomal storage disease (MPS)
- Lysosomal storage disease (mucopolysaccharidoses)